> Fundamentally it isn't a database, period. It's a schema for files in a file system.
This is false. It is both.
A database is merely an application that provides an interface to structured data on disk.
I know a thing or two about databases, having contributed to a few of the larger open source ones.
There's a lot more to TreeBase than is on the website right now. As the website says "We have been using TreeBase for over 2 years in systems with millions of rows and dozens of collaborators." For all you know, you may have actually used a website that is powered by TreeBase (well, a TreeBase application written in a different host language, but the file system semantics are the same).